Oyaide FTVS 510 is a simple 75ohm solid core silver coax cable with teflon dielectric.
Apart from being a silver core & silver plated copper braid, its a coax cable.
Its more suitable for a digital IC with the solid core, but will be OK for an analogue pair provided its not bent & moved around too much.
Its sold as a bulk cable by Oyaide & you can buy it as cut cable or as a made IC from a number of outlets. Mark seems to be selling at the lowest price per metre.
No reviews around www that I can find, but some of the usual forum chatter.